Selective telephone call system.



0. N. LINDSEY. SELBGTWB TELEPHONE GALL SYSTEM.

APPLICATION FILED AUG.20, 1909.

Patented Feb. 11, 1913.

3 SHEETS-SHBET 1.

N e 1. e@ kb w of *www* 1%@ m @w \1 me Q NQ@ 11 w 11 QQ N w M M N n E@ *mi eq 1% j: 1 j\ N elmunmne i N Q5 N k 'N u N y N N. N (H1 N W@ R QN Wtnesses Inventor COLUMBIA PLANoGRAPn co..rasmxic'ro' nA c.

0. N. LINDSEY.

y SBLEGTIV'B TELEPHONE GALL SYSTEM.

APPLICATION FILED -AUG.20, 1909. 1,053,048 l Patented Feb. 11, 1913.

3 SHEETS-SHEET 2.

Witnesses I Inventor by L Y l* Attorney cohmuxm PLANUGRAPM bu.,wA5mNG ToN, u c.

0. N. LINDSEY.

SELBCTIVE TELEPHONE GALL SYSTEM. APLIGATION FILED AUG. 20, 1909.

Patented Feb. 11, 1913.

3 SHEETS-SHEET B.

JZ' J OSCAR NEELY LINDSEY, OF SENATOBIA, MISSISSIPPI, ASSIGNOR OF THIRTY ONE- HUNDREDTHS TO JOHN W. HALL, OF MEMPHIS, TENNESSEE.

SELECTIVE TELEPHONE CALL SYSTEM.

Application filed August 20, 1909.

T 0 all whom t may concern.'

Be it known that 1, Osons N. LiNDsEY, a citizen o the United States, residing at Senatobia., in the county of Tate and State ot- Mississippi, have invented a new and useful Selective Telephone Call System, of which the following is a specification.

This invention has reference to improvements in selective telephone call systems and its object is to provide a call system wherein the selectivity is caused by the successive action of cut outs at successive stations in. order from the central station to the called station.

In accordance with the present invention, there is provided at the central station, a means for sending successive impulses onto the line, corresponding to the number of stations to be signaled, and at each station there is an apparatus capable of cutting in the call circuit at each station upon the reception ot one impulse, and then cutting out the. call circuit at the said station, upon the reception' or" a succeeding impulse. There is also provided at each station a means responsive to another impulse sent over the line but of a different character from the irst impulses for resetting all the instruments at all the stations which have been atlected.

The invention will be best understood from a consideration of the following detail description taken in connection with the accompanying drawings forming a part of this specification, in which drawings-- Figure 1 is a diagrammatic representation of the selective telephone call system including the apparatus at the central station and at successive local stations. Fig. 2 is a similar view showing a somewhat modified form of the apparatus. Fig. 3 is a side elevation of the cut-out mechanism employed in connection with the system shown in Fig. 1. Fig. 4 is a similar view of another form of cut-out mechanism such as used in connection with the system of Fig. 2. Fig. 5 is a vertical cross section of the structure of Fig. 4, between the twomagnets there shown and looking toward the right. Fig. G is a detail elevation ot' a portion ot' the armature lever and the spring lingers carried thereby; F ig. 7 is a d-etail perspective oit a portion of the form of apparatus depicted in Fig. 2; and Fig. 8 is an elevation of a portion of the form of appa- Specification of Letters Patent.

ratenteareb. ii, isis.

Serial No. 513,843.

ratus shown in Fig. 2, the view depicting the spring linger and certain of the elements which coperate therewith.

Referring' to the drawings there is shown in Figs. 1 and 2 a central station A and two successive local stations B and C, it being understood that the local stations are to be taken simply as indicative of any suitable number of successive stations in communication wit-h the central station A. Furthermore sincethe present system has no special reference to the talking circuit, the switch board mechanism has been omitted from the showing of the central station A. At t-he central station A there is a switch arm 1 having its free end capable of making successive contact with a connected series of contacts 2 between which contacts are insulating blocks 3 upon which the switch arm 1 may rest out of engagement with adjacent contacts 2. The contacts 2 are all connected to a conductor 4. The switch arm 1 is connected to a conductor 5 and these two conducto-rs 4 and 5 lead to binding posts 6 mounted on a base 7 carrying the switch arm and the contacts. It will of course be understood that this showing is illustrative and that the switch arm and contacts may be otherwise mounted than upon a base 7.

In t-he system there ar-e provid-ed three line conductors 8, 9, and 10, the conductors 8 and 10 being continuous t-hroughout the system while the conductor 9 is carried into each local station and there disposed as will hereinafter appear. The binding post 6 receiving the conductor 5 is connected by a conductor 11 to the conductor 10 and this conductor 11 includes a battery 12 or other suitable source of electric energy preferably of the continuous current type. The binding' post 6 receiving the conductor 4 is connected loy another conductor 13 to the conductor 9. Leading from the conductor 13 to another binding post 14 on the base 7 is a conductor 15 and connected to the binding post 14 is a circuit terminal 1G. The circuit terminal 16 is in the path ot a key or switch arm 17 connected to a binding post 18 on the base 7 and this binding post is connected to ground through a conductor 19. There is also provided at central a magneto generator 2O which may be taken as typical of any generator of alternating current and this generator is connected on the side opposite to that connected to the conductor 15 by another conductor 21 to the line conductor 8.

i By moving the switch arm 1 from one contact 2 to the next in order throughout the series, a like, number of closures of the circuit of the battery 12 upon the line conductors 9 and 10 may be caused, these closures of the circuit always beginning with a certain one, and preferably the end one, of the series of contactsl and progressing successively toward the other end of the series as far as may be desired. By closing the key or lever 17 down on the contact 16 the generator 2O may be closed upon the conductor 8 on o-ne side and to ground on the other side. The purpose of these operations will appear hereinafter.

At each localstation there is a signal bell 22 shown as of the ordinary polarized type and therefore needing no special description and there is also provided at each local station a telephone unit 23 which also may be of the usual type and requires no special description, the showing of the drawing being simply illustrative of any approved type of telephone unit, the said unit comprising both the transmitting and receiving devices. On one side the signal bell 22 is connected by a conductor 24 to the main line conductor 8 and one side of the telephone unit 23 is also connected by a conductor 25 to this same conductor 24. The other side of the telephone unit 23 is connected by a conductor 26 to another conductor 27 in turn connected to the line conductor 10. It will be seen that the main line conductors 8 and 10 have bridged between them at each local station the telephone unit 23, so that considering the conductors 8 and 10 as a multi-party line, conversation may be carried on in the usual manner. There is also located at each local station a device for cutting the signal bell 22 into and out of circuit. In the drawings two forms of such device are shown and reference will therefore be had first to the showing of Figs. 1 and 3.

Mounted on a suitable base 28 is an electromagnet 29 and erected on the base adj acent to the magnet is a post or standard 30 carrying a lever 31 fastened to which there is an armature 32 in operative relation to the electromagnet 29.

On o-ne side of the standard 30, the lever 31 has secured thereto a spring 33, the other end of which spring is made fast to the base 28 or to some other point while the other end of the lever beyondthe magnet 29 carries a pendant bar 34 having its free end notched to form a shoulder 35 and this bar is normallv constrained toward the magnet 29 by a spring 36 attached at one end to the bar and at the other end to t-he lever 31. On the base 28 there are two adjacent spring members 37 and 38, the member 38 having its free end in operative relation to the shoulder 35 at the lower end of the bar 34.

One side of the loop of the conductor 9 entering the local station is carried to a binding post 39 on the base or support 28 and from this binding post 39 there leads 'a conductor 40 to one side of the magnet 29 while the other side of this magnet is connected by a conductor 41 to the spring strip 38. The strip 37 l is connected by a conductor 42 to a binding post 43 to which the conductor 27 before referred to is also connected so that the strip 37 is connected through the conductor 42, binding post 43, and conductor 27 to the main line conductor 10. lf now the switch 1 at the central station be moved on to one of the contacts 2 corresponding to the station under consideration, and by way of example let it be assumed that the first local station is the one to be considered then the switch arm 1 is moved o-nto the lirst of the series of contacts 2 and an impulse is transmitted from the battery 12 through the conductor 11 thence by way of the conductor 5 through the switch arm 1 to the lirst contact 2 thence by way of conductor 4 to the conductor 13 and by the latter to the main line conductor 9 entering the first local station at the binding post 39, thence the circuit may be traced thro-ugh the magnet 29, conductor 41, strip 38, strip 37, conductors 42 and 27 to the main line conductor 1() and thence back to the battery 12.

Under normal conditions the bar 34 is in the elevated position with the shoulder 35 above the spring strip or linger 38 and out of engagement therewith. When the circuit is completed in the manner described then the magnet 29 is energized and the armature 32 is attracted thus causing the armature lever 31 to move against the action of t-he spring 33 and lower the bar 34 until the notch in the lower end of the bar is brought opposite the end of the spring linger 38 when the reaction of the spring 36 will cause the shoulder' 35 to snap under the spring linger 38. So long as the lever 1 remains upon the first contact 2 the magnet 29 remains energized and the spring lingers 37 and 38 remain 'in contactsince the snapping of the shoulder 35 beneath the spring linger 38 has not interfered with the normal condition of contact between these two tingers. When, however, the magnet 29 is deenergized the action of the spring 33 is to causea movement of the lever 31 in a direction raising the bar 34 and since the shoulder 35 is now in engagement with the spring linger 38 the lat-ter is lifted from contact with the spring linger 37 and the circuit at this point is broken so that subsequent impulses sent through the conductors 9 and 10 will notl traverse the magnet 29.

Mounted on the lever 31 are three superposed spring fingers 44, 45, and 46 insulated one from the other and from the lever 31. The spring finger is longer than the spring fingers 44 and 46 and is intermediate thereof and is adapted to make contact with both fingers 45 and 46 but not both at the same time.

ln the path of' the free end of the finger 45 are opposed members 47 of a bracket 48 secured to,and projecting from a post. or standard 49 erected on the base or support 28. The opposed members 47 on the bracket 48 are so related to the spring finger 45 that when the lever 31 moves through the eXtent of its travel in one direction one of' the members 47 will engage the spring finger and hold the same against further movement with the lever 31 and when the vlatter is moved to the other extent of its travel in an opposite direction the other member 47 will engage the spring fing-er 45 and hold it against further movement with the lever 31, in the said other direction. rlhe extent of travel of the lever 31 is sufficient to carry one or the other of the spring fingers 44 and 46 into electrical contact with the spring finger 45 when the latter is arrested by engagement with the corresponding member 47 of' the bracket 48. Thus when the lever 31 is moved toward the magnet 29 the finger 45 is brought into electrical engagement with the finger 44. hen the lever 31 is moved away from the magnet 29 under the influence of the spring 33 then the finger 46 is brought into electrical engagement with the finger 45. lfhen the lever 31 is in the normal raised position then the spring ngers 45 and 46 are in electrical engagement. rlhe spring finger 45 is connected by a conductor 50 to the binding post 39. The finger 44 is connected by a concluetor 51 to a binding post 52 and leading from this binding post is a conductor 53 coupled to the side of the bell 22 remote from that coupled to the conductor 24. The spring finger 46 is connected by a conductor 54 to a binding post 55 and to this binding post is connected the end of' the conductor 9 leaving the station, the entering end of this conductor being connected to the binding post 39.

Then the switch arm 1 is moved upon the first of the series of contacts 2, the following circuit is established at stations A and B: the battery 12, the conductor 11, the conductor 5, the lever 1, the contact 2, the conductor 4, the conductor 13, the conductor 9, the conductor 40, the winding of the electro-magnet 29, the conductor 41, the spring members 38 and 37, the conductor 42, the conductor 27, the conductor 10, and the battery 12, The magnets 29 in all of the local stations will be energized, attracting the several armature levers 31. However, before the armature levers 31 have moved sufficiently to permit the shoulder 35 of any of the bars 34 to engage with any of the spring fingers 38, the spring members 45 and 46 at station B will have separated, and thus the line circuit beyond the station B will be broken. The free ends of the armature levers 31 at all stations, saving station B, will rise under the action of the springs 33, Without having caused the shoulders 35 to snap beneath the spring tongues 38. Since the magnet 29 of stat-ion B is energized, the bar 31 at station B will continue to descend until the shoulder 35 is snapped beneath the spring finger 38. So long, however, as the magnet 29 is energized, the armature leverl 31 at station B will not rise, and consequently the bar 34 will not work a separation of the spring fingers 38 and 37. The downward movement of the armature lever 31 at station B serves to bring the spring fingers 45 and 44 into contact. Under such circumstances, the following circuit is established: the magneto 20, the conductor 15, the conductor 9, the binding post 39, the conductor 50, the finger 45, the finger 44, the conductor 51, the post 52, the conductor 53, the bell 22, the conductor 24, the conductor 8, the conductor 21, and the magneto 20. lf the magneto 2O is now operated, it will be readily understood that the bell 22 at station B will give a signal. Suppose however that some subsequent station is to be the called station and not station B, then instead of causing the ringing of the signal in the manner described, the switch 1 is moved from contact number 1 to contact number 2. This will cause the denergization of' the magnet 29 since the switch arm 1 does not bridge two contacts but passes from one to the other and thus the circuit is broken. Vhen the magnet 29 is denergized the shoulder 35 already underriding the spring finger 38 causes the breaking of the circuit including the magnet, and the said spring members 37 and 38 so that the magnet 29 is then cut out of the circuit.

The raising of the lever 31 under the action of the spring 33 has caused the engagement of the spring lingers 45 and 46 so that when the switch arm is moved on to the next succeeding contact 2 there is established a circuit. Starting at the battery 12 the circuit traverses the conductor 11 and conductor 5 to the switch arm 1, thence to the contact 2 thence by way of conductors 4 and 13 to the main line conductor 9, thence to the binding post 39 at station B, thence by conductor 50 to the spring finger 45, thence to spring finger 46 and by conductor 54 to the binding post 55, thence from the station by the continuation of the conductor 9 to station C, thence through the magnet 29 of station C, thence by conductors 42 and 27 at station G to conductor 10 and back to the battery. The magnet 29 of station B being cut out of circuit this second impulse will set up at station C circuit conditions already described with relation to stat-ion B before the magnet 29 was denergized. Now on moving the switch arm 1 to the third contact 2 the magnet 29 at station C is cut out and the circuit through the conductor 9 reestablished as already described with relation to station B. So the conditions from station to station may be established as described by moving the switch arm 1 from Contact 2 to contact 2 through as many contacts as may be necessary to establish signal. conditions at the desired station when the magneto 2O may be operated and the signal produced at the last station affected. However all the stations between the central station and the called station are now in the signal-cut-out condition and in order that the system may be operative for subsequent calls it is necessary after a station has been called and the talking circuit -has been then established and the subscribers are through with the line to reset the several cut-outs to the normal condition. For this purpose at each station the post or standard 49 carries an electromagnet 56 having an armature 57 a portion 58 of which serves as a convenient place of attachmentfor a link 59 whereby the armature is connected to the bar 34. One side of the magnet 56 at each stat-ion is grounded through a conductorf60, the other side is connected to a conductor 61 which in turn is connected to the conductor 24 but this conductor 61 includes a condenser 62 so that this circuit may be traversed by alternating currents generated by the magneto 20. By now closing the switch arm 17 on to the contact 16 there is established a circuit from the magneto 20 through the conductor 21 to the conductor 8 thence by the conductors 24 and 61 through the condenser 62 to the magnet 56 at all the several stations in multiple thence to gro-und through the respective conductors 60 and romthe ground through the conductor 19, switch arm 17, contact 16, and the connections therefrom back to the magneto 20.

The general electric circuits of the system of Fig. 2 are the same as those of Fig. 1, the system diilering however in the details of construction of the cut-out mechanism which is shown more in detail in Figs. 4 and 5, to which, together with Fig. 2 reference will now be had. The magnets 29 and 56 will remain as before but the lever 31 carries but one spring finger 45 connected by a conductor 50 to the binding post 39. rlhe lever 31 carries a cross arm 63 to which the linger 45 is directly connected and this cross arm, which may be made of insulating material, also carries a finger 64 parallel with the spring linger 45. The magnet 56 has it-s armature 57 supporting a block 65 and this block carries on the face remote from the magnet 56 but facing the magnet 29 a slide 66 the lower end of which is bent to form an angle finger 67 while at the upper end there is formed a boss or projection 68 in the path of the linger or arm 64. rIhe block 65 swings with the armature 57 but the eX- tent of its movement away from the magnet 56 is limited by a bracket 69 carried by posts or standards 7 O erected on the base 28. The lower bent end 67 of the slide 66 engages the spring linger 71 which normally rests upon a circuit terminal 72 on the base 28 but may be separated therefrom by the upward movement of the slide 66. The posts or standards carry an insulating block 73 on opposite sides of which are strips 74 and 75 with approaching ends in the path of the free end of the spring finger 45. The strip 74 is connected by a conductor 76 to the binding post 52. The strip 75 is connected to the binding post 55 by a conductor 77. The magnet 29 is connected to the spring strip or finger 71 by a conductor 41 and the circuit terminal 7 2 is connected by a conductor 42 to the binding post 43 as in thev structure of Fig. 1. I

l/Vhen a magnet 29 of the system shown in Fig. 2 is energized then the lever 31"is attracted and the spring linger 45 is brought into engagement with the strip 7 5 thus completing the signal circuit and so that signals may now be sent as before. At the same time the arm or linger 64 has been moved downward until it engages under the boss 68. of the slide 66. l/Vhen the magnet 29 is deenergized the lever 31 is raised by its spring 33 and the arm or finger 45 is brought again into engagement with the strip 74 completing the circuit through the conductor 9 to the next station and at the same time completing the circuit between the strips 71 and 72, the electrical circuit being the Ysame as described with reference to Fig. 1. Nhen it is desired to reset the cut-out then the magnets 56 are energized as before drawing the block 65 away from its normal position to a sufficient extent to carry the boss 68 out of the path of the arm 64 and the slide 66 station; means at each station controlled byI said magnet for closing the signal circuit through the signal at said station; means at each station operated by the said magnet, 'for cutting out from the selecting circuit all magnets farther :trom said source while the said magnet remains energized; and means operative upon the denergization of the magnet thus cutting out the other magnets, to prevent energization of said magnet upon a second impulse.

2. In a signal system, a selecting circuit including a magnet at each station; a source of selecting current supply; means for sending impulses from said source; a normally open signal circuit including a signal at each station; means at each station contro-lled by said magnet for closing the signal circuit through the signal at said station; means at each station operated by the said magnet, for cutting out from the selecting circuit all magnets farther from said source While the said magnet remains energized; and means operative upon the denergization of the magnet thus cutting out the other magnets, to prevent energization of said magnet upon a second impulse; and independent, electro-magnetic means for rendering inoperative the preventing means.

3. in a signal system, a selecting circuit including a magnet at each station; means for sending current impulses through the selecting circuit; a signal circuit including a signal at each station; means at each station operated by said magnet for controlling the signal circuit through the signal at said station; means at each station operated by the said magnet, for cutting out from the selecting circuit all magnets farther from said sending means while the said magnet remains energized; and means operative upon denergization of the magnet so cutting out the other magnets, to prevent energization of the said magnet upon a second impulse.

a. in a signal system, a selecting circuit including a magnet at each station; means for sending current impulses through the selecting circuit; a signal-circuit including a signal at each station; means at each station operable by said magnet for controlling the signal-circuit through the signal at said station; and for opening the select-ing circuit between said magnet and the magnets farther from said sending means than said magnet, thereby to cut out from the selecting circuit, all magnets farther from said sending means While the said magnet remains energized; and a circuit-breaker operative upon the denergization of the magnet so cut-ting out the other magnets, to open the selecting circuit between said magnet and said source; the magnetically operated means operating upon a denergization of said magnet, to close the selecting circuit between said source and a farther magnet.

In testimony that l claim the foregoing as my own, have hereto aiiixed my signature in the presence of two Witnesses.

@SCAR NEELY LIND SEY.

1Witnesses W. J. Ensr, A. A. ROYALL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

